Commercial field detection kits for Clavibacter michiganensis subsp. michiganensis (Cmm) have historically been limited to immunoassay-based formats such as ELISA and lateral flow-based technologies.
While effective for high-throughput screening purposes, they are known to cross-react with other Clavibacter michiganensis subspecies, as well as some non-pathogenic bacteria that persist in soil.
The cross-reactivity of these methods mandates confirmation testing of positive results by a laboratory equipped for PCR, media plating, and microscopy detection.
These confirmatory laboratory techniques may delay critical management decisions to stop the spread of the pathogen.
We have developed a rapid isothermal DNA amplification kit using the AmplifyRP® XRT platform, based on the recombinase polymerase amplification (RPA) technique, for Cmm detection.
The kit uses specific primers and a probe for real-time fluorescence detection on crude extract in a 20‑minute test, which successfully identifies the presence of Cmm in bacterial culture, tomato fruit, stem, and petiole.
Data will be presented on an external validation of the Cmm AmplifyRP® XRT kit collected by an outside seed company.
The kit provides a fast and convenient detection method that retains the sensitivity and specificity of PCR while reducing the complexity of molecular diagnostics for inexperienced users.